HIF-1 induced tiRNA-Lys-CTT-003 is protective against cisplatin induced ferroptosis of renal tubular cells in mouse AKI model.

HIF-1 activation is protective in acute kidney injury (AKI), but its underlying mechanism is not fully understood. Stress-induced tRNA derived small RNAs play an emerging role in cellular processes. This study investigated the role of HIF-1 associated tiRNA-Lys-CTT-003 (tiR-Lys) in an AKI mouse model. Our sequencing results showed that ischemia can promote the production of renal tiR-Lys by activating HIF-1α. FG-4592, a HIF-1 inducer, can also upregulate the expression of tiR-Lys in renal tubular cells. Both overexpression of tiR-Lys and FG-4592 pre-treatment could improve mitochondrial damage and lipid peroxidation with alleviated renal function and morphological damage in cisplatin-induced AKI mice. While the anti-ferroptosis effect of FG-4592 were largely eliminated by tiR-Lys inhibitor. Notably, tiR-Lys directly alleviated cell death and MDA accumulation induced by the ferroptosis inducer Erastin, accompanied with restored expression of GPX4. RNA-Pulldown and RIP-qPCR results revealed that tiR-Lys can interact with the RNA-binding protein GRSF1.tiR-lys overexpression can preserve protein expression of GRSF1 decreased by cisplatin. Inhibiting Grsf1 via shRNA eliminated the upregulation of GPX4 by tiR-Lys. In conclusion, our study demonstrates that HIF-1α-induced tiR-Lys is protective in cisplatin-induced AKI, primarily by upregulating the level of GPX4 through interaction with GRSF1, thereby inhibiting ferroptosis in renal tubular epithelial cells.

Association of the triglyceride-glucose index with all-cause and cardiovascular mortality in patients with cardiometabolic syndrome: a national cohort study.

OBJECTIVE: This study aimed to evaluate the association of triglyceride-glucose (TyG) index with all-cause and cardiovascular mortality risk among patients with cardiometabolic syndrome (CMS). METHODS: We performed a cohort study of 5754 individuals with CMS from the 2001-2018 National Health and Nutrition Examination Survey. The TyG index was calculated as Ln [fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2]. Multivariate Cox proportional hazards regression models assessed the associations between TyG index and mortality . Non-linear correlations and threshold effects were explored using restricted cubic splines and a two-piecewise Cox proportional hazards model. RESULTS: Over a median follow-up of 107 months, 1201 all-cause deaths occurred, including 398 cardiovascular disease-related deaths. The multivariate Cox proportional hazards regression model showed a positive association between the TyG index and all-cause and cardiovascular mortality. Each one-unit increase in the TyG index was associated with a 16% risk increase in all-cause mortality (HR: 1.16, 95% CI 1.03, 1.31, P = 0.017) and a 39% risk increase in cardiovascular mortality (HR: 1.39, 95% CI 1.14, 1.71, P = 0.001) after adjusting for confounders. The restricted cubic splines revealed a U-shaped association between the TyG index and all-cause (P for nonlinear < 0.001) and cardiovascular mortality (P for nonlinear = 0.044), identifying threshold values (all-cause mortality: 9.104; cardiovascular mortality: 8.758). A TyG index below these thresholds displayed a negative association with all-cause mortality (HR: 0.58, 95% CI 0.38, 0.90, P = 0.015) but not with cardiovascular mortality (HR: 0.39, 95% CI 0.12, 1.27, P = 0.119). Conversely, a TyG index exceeding these thresholds was positively associated with all-cause and cardiovascular mortality (HR: 1.35, 95% CI 1.17, 1.55, P < 0.001; HR: 1.54, 95% CI 1.25, 1.90, P < 0.001, respectively). Notably, a higher TyG index (≥ threshold values) was significantly associated with increased mortality only among individuals aged under 55 compared to those with a lower TyG index (< threshold values). CONCLUSIONS: The TyG index demonstrated a U-shaped correlation with all-cause and cardiovascular mortality in individuals with CMS. The thresholds of 9.104 and 8.758 for all-cause and cardiovascular mortality, respectively, may be used as intervention targets to reduce the risk of premature death and cardiovascular disease.

Lyn attenuates sepsis-associated acute kidney injury by inhibition of phospho-STAT3 and apoptosis.

Sepsis-associated acute kidney injury (SA-AKI) is a life-threatening condition associated with high mortality and morbidity. However, the underlying pathogenesis of SA-AKI is still unclear. Lyn belongs to Src family kinases (SFKs), which exert numerous biological functions including modulation in receptor-mediated intracellular signaling and intercellular communication. Previous studies demonstrated that Lyn gene deletion obviously aggravates LPS-induced lung inflammation, but the role and possible mechanism of Lyn in SA-AKI have not been reported yet. Here, we found that Lyn protected against renal tubular injury in cecal ligation and puncture (CLP) induced AKI mouse model by inhibition of signal transducer and activator of transcription 3 (STAT3) phosphorylation and cell apoptosis. Moreover, Lyn agonist MLR-1023 pretreatment improved renal function, inhibited STAT3 phosphorylation and decreased cell apoptosis. Thus, Lyn appears to play a crucial role in orchestrating STAT3-mediated inflammation and cell apoptosis in SA-AKI. Hence, Lyn kinase may be a promising therapeutic target for SA-AKI.

ATP-citrate lyase inhibitor improves ectopic lipid accumulation in the kidney in a db/db mouse model.

Aim: We evaluated a novel treatment for obesity-related renal, an ATP-citrate lyase (ACL) inhibitor, to attenuate ectopic lipid accumulation (ELA) in the kidney and the ensuing inflammation. Materials and methods: An ACL inhibitor was administered intragastrically to 12-week-old db/db mice for 30 days. The appearance of ELA was observed by staining kidney sections with Oil Red O, and the differences in tissue lipid metabolites were assessed by mass spectrometry. The anti-obesity and renoprotection effects of ACL inhibitors were observed by histological examination and multiple biochemical assays. Results: Using the AutoDock Vina application, we determined that among the four known ACL inhibitors (SB-204990, ETC-1002, NDI-091143, and BMS-303141), BMS-303141 had the highest affinity for ACL and reduced ACL expression in the kidneys of db/db mice. We reported that BMS-303141 administration could decrease the levels of serum lipid and renal lipogenic enzymes acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), HMG-CoA reductase (HMGCR), and diminish renal ELA in db/db mice. In addition, we found that reducing ELA improved renal injuries, inflammation, and tubulointerstitial fibrosis. Conclusion: ACL inhibitor BMS-303141 protects against obesity-related renal injuries.